1. Field of the Invention
The present invention relates to the use of extensible mark-up language (XML) based time markers to provide navigation entry points for navigation of a synchronized multimedia presentation.
In particular, the invention concerns label-based navigation for entry points into a multimedia presentation, that allow the user viewing the multimedia presentation to begin the presentation from any of pre-defined entry points defined by the labels which may be text-based, icon-based or image-based.
2. Description of the Related Art
Various mark-up languages have been proposed for use in Internet and Intranet browsing of web-based pages. Currently, the most popular mark-up language is hypertext mark-up language (HTML). HTML defines spatial relationships and visual appearance of a web page when the page is displayed at a user""s browser.
One disadvantage of HTML is that it is difficult to display a multimedia presentation using HTML alone. Moreover, it is nearly impossible to synchronize different multimedia presentations within the same web page. Thus, although with HTML it is possible, though difficult, to display a video file, it is nearly impossible to synchronize two different video files for simultaneous display on the same web page.
In response to these shortcomings, the World Wide Web Consortium Working Group on synchronized multimedia has proposed an extensible mark-up language (XML) based language that permits synchronization of multimedia presentations. A proposed standard has been circulated, entitled xe2x80x9csynchronized Multimedia Integration Languagexe2x80x9d (SMIL), version 1.0, the contents of which are incorporated herein by reference. Importantly, the SMIL standard permits both sequential and parallel presentation of multimedia files, thereby permitting synchronization either serially or parallelly of multimedia presentations.
Despite the advantages of the SMIL standard, the standard still only provides for limited user intervention in the multimedia presentation. In particular, it is not now possible, using the SMIL standard, for a user to control the entry point into the multimedia presentation, such that the user can start the multimedia presentation from a desired starting point. Rather, using SMIL, it is only possible for a user to begin the multimedia presentation at the beginning, to fast forward or skip forward through the multimedia presentation, and to stop and to pause it.
It is therefore an object of the invention to provide XML-based time markers that allow navigation into a synchronized multimedia presentation, such that a user is able to begin the multimedia presentation commencing from any of plural pre-defined text-based entry points.
Thus, in one aspect, the invention is an XML-based time marker that includes, as content thereof, up to plural label-based list elements. The labels may, for example, be text, icons, or images. Each list element, in turn, includes items that correspond to multimedia elements defined by SMIL standard. Each list element corresponds to an entry point in the multimedia elements. Accordingly, each item within a list element defines the entry point of a parallelly-synchronized portion of a SMIL-based multimedia presentation.
In a further aspect of the invention, a SMIL-based browser using a time marker according to the invention responds to an encounter with the time marker as follows. Specifically, upon encountering a time marker element, the browser parses the time marker so as to identify each label-based list element. A user interface is created and displayed, with the user interface including a label corresponding to the labels in each list element. Thus, the user interface may contain text, icons or images, in dependence on the nature of the list elements. In addition, the browser maintains a place holder, such as an internal look-up table corresponding to the entry point in the SMIL-based multimedia presentation, as defined by the items in each list element in the time marker. The browser displays the multimedia presentation according to the SMIL standard. Responsive to user selection of one of the labels in the user interface, the browser causes the multimedia presentation to be synchronized to the entry point corresponding to that list element, and to commence playback of the multimedia presentation from that entry point.
By virtue of the foregoing, a user is able to navigate more readily through a multimedia presentation, by commencing and re-commencing the presentation at any entry point defined in the time marker.